Petronet LNG and Havells India will be included in the index in their place, BSE said in a circular.
Sensex Next 50 index measures the performance of the subsequent 50 largest index-eligible stocks outside the BSE Sensex 50.
The exchange said that United Spirits has been dropped from the index as it no longer meets the index eligibility criteria.
Further, Cairn India would move out from the index due to suspension of trading in its shares from April 26 as the cash-rich oil producer has merged into its debt-ridden parent Vedanta.
Apart from Sensex Next 50 index, Cairn India would be dropped from indices including energy and infrastructure.
Last week, the exchange said it would discontinue equity as well as equity derivative trading in the security of Cairn India from April 26.
Under the merger deal, shareholders of Cairn India will get one equity share of Vedanta and four redeemable preference shares of face value Rs 10 and coupon 7.5 per cent.
Further, Cairn India shareholders, as on record date, who will become shareholders of Vedanta, would also receive an interim dividend of Rs 17.70 per equity share. The record date for the share swap has been set as April 27.